The leading architects of Brexit populism display a troubling pattern of attacking judges in a manner that goes far beyond the tension between government and the judiciary required for the functioning of democracy. It is desirable for there to be stress between the bench and the executive. If there was complete harmony between the two centres of power then voters ought to worry. But the strain ought not lead to conflict of a serious nature.

The flashpoint this week is over judicial review, an essential check on government overreach and abuse. The court of appeal’s decision to halt the deportation of detainees unable to exercise their legal right to contact their lawyers has been impugned as vexatious by Downing Street. The door is being opened to a weakening of this protection against an overmighty state on the grounds that legal challenges to ministerial decisions were being used, in Boris Johnson’s words, to “conduct politics by another means”.

It was government defeats in two judicial reviews in the supreme court in the wake of the 2016 Brexit referendum that placed judges, unwittingly perhaps, on the losing side of a culture war. Branded “enemies of the people” by the Daily Mail, and their decisions decried as “wrong” by Boris Johnson, the judiciary are firmly in the sights of the victorious Brexiters. Mr Johnson has lost no opportunity to ram this message home. Skulking in the Conservative manifesto were references to massive potential changes to the relationship between government, parliament and the courts.

Two instruments are being floated, notes Lord Falconer, to reduce the courts’ vigilance to servility. The first aims to give ministers a say in judicial appointments. The second proposes that parts of the royal prerogative are put off limits to judicial review. Both would be extremely retrograde steps and fetter judicial independence. No government ought to think it right to pack a court, or give the impression that it could, by asking judges to give up their opinions or their place. At worst this is pure Trumpism: an attempt to remake the courts in Johnson’s own image. At best it would turn the clock back more than 15 years to a different political age when lord chancellors had such powers but were substantial legal figures in their own right, and usually, as Prospect magazine pointed out, resisted the temptation to pick pliable jurists.

The second thrust of Mr Johnson’s charge is even more troubling. As Sir Stephen Sedley, a former appeal court judge, has noted, one of the signal achievements of the last century was “the power of the courts to supervise the legality of perogative acts of the Crown”. It was through this mechanism that the home secretary was found liable for contempt of court in the case of wrongful deportations and that it was ruled, in the case of Prince Charles’ black spider memos, the attorney general could not overturn court decisions because he disagreed with them. Judges know their limits – for example saying that the issue of assisted dying is one for parliament to decide. Public law has a proper sphere of operation which does not include the operation of government. Yet the state must operate within the law and the courts must be able to guard against the elected dictatorship afforded by a parliamentary majority acting otherwise.